Re: Should pivot.wtk.Dimensions/Insets/CornerRadii/Bounds be immutable?

[Greg Brown <gk...@mac.com>]

>The primary disadvantage is the increased creation of temporary
>objects in current VMs.

Help me to understand this. Currently, these data structures are declared as non-final but otherwise have the same semantics (public member access). For the most part, we wouldn't be changing how they are used, so I don't understand how this would translate to creation of any more temporary objects than we currently have. What would cause additional temporary objects to be created?

>Do you have any performance test cases that you use? I could put
>together some changes and see what the numbers look like before and
>after.

Unfortunately, we don't have any unit tests that would be useful here. But I think it is reasonably safe to assume that we might see a slight performance improvement by making this change.

Re: Should pivot.wtk.Dimensions/Insets/CornerRadii/Bounds be immutable?

[Todd Volkert <tv...@gmail.com>]

>>The primary disadvantage is the increased creation of temporary
>>objects in current VMs.
>
> Help me to understand this. Currently, these data structures are declared as non-final but otherwise have the same semantics (public member access). For the most part, we wouldn't be changing how they are used, so I don't understand how this would translate to creation of any more temporary objects than we currently have. What would cause additional temporary objects to be created?

If I understand Noel correctly, he's saying that since the objects are
immutable, we may be forced to instantiate new objects where we were
previously modifying the properties of existing objects.

>>Do you have any performance test cases that you use? I could put
>>together some changes and see what the numbers look like before and
>>after.
>
> Unfortunately, we don't have any unit tests that would be useful here. But I think it is reasonably safe to assume that we might see a slight performance improvement by making this change.

IMHO, the performance improvement (or degradation) is likely to be so
minor as to not matter - the major advantage is the reduction in
developer error and ambiguity.

I'm +0.5 on this change. :)